Painting the walls of your pool may seem like a simple action that changes the color of your pool walls. Due to the nature of the pool, this is not as simple or easy as it appears.
The primary issue with painting the walls of your pool is something called "chalking." Chalking is a process that causes a chalky white powder to form on the surface of paint. It is on the paint's film that this layer forms. Typically, chalking occurs as a result of sunshine and moisture, two things that are not uncommon to find in a pool. Ordinarily, this occurs as a result of weathering and occurs over a long enough period not to be a huge issue. What happens is that the paint's binder is weakened by moisture and sunlight, over time failing and releasing its pigments.
Naturally, this problem is far worse in pools. Being constantly submerged drastically increases the speed at which chalking occurs. Paint kept constantly wet will very quickly begin chalking. Sunset Pools & Spas, a company specialized in pool resurfacing in Chicago, warns, “Painting the inside of your pool will cause chalking to occur in a very short time frame.”
The reason chalking is a major issue for pools is that the chalky white powder that builds up on the paint film will not stay there. Instead, the chalky powder will diffuse into the surrounding water. This will result in your pool attaining a murky quality. A white powder mixing with the pool water will make it appear dirty and unsafe. Pools appear substantially less appealing when their water is vaguely off-white rather than clear. Clear water is always preferable to dusky water filled with white powder.
It is for this reason that painting your pool walls is simply a bad idea. As a result of the submerged and often sunny conditions, paint deteriorates at an incredibly rapid rate. The fact that paint simply cannot endure the conditions of a pool without devolving into a powdery mess means that painting the walls of your pool is going to do more aesthetic harm than good.
Painting your pool walls just causes the formation of a white powder on the paint. It is best to avoid the problem of chalking by not painting the interior of your pool. This is far preferable to having to endure the problem of cloudy water filling your pool and making it both hard on the eyes and not desirable to use.